Coaxial connector having one-piece clamp assembly

ABSTRACT

A clamp-type coaxial connector having a one-piece clamp assembly. The clamp assembly includes a clamp nut, a clamp bushing, and a clamp ferrule. The nut and bushing each include a member adapted to coact with the member of the other element to secure the nut and bushing together in a manner such as to permit limited axial movement between the elements. The nut is adapted to coact with a connector body to secure the clamp assembly to the body and to drive the nut and bushing toward each other. A counter-bore exists in the nut and/or the bushing in which the ferrule is captivated, the counter-bore having an angled surface which coacts with the ferrule as the nut and bushing are driven toward each other to clamp the ferrule against the outer conductor of a coaxial cable.

United States Patent us) 3,676,573 Avery 5] July 11, 1972 s41 COAXIAL CONNECTOR HAVING ONE- 3,498,647 3/1970 Schroder ..174/75 c x PIECE CLAMP ASSEMBLY Roger Peter Avery, Bethe], Conn.

The Bunker-Ramo Corporation, Brook, Ill.

June 22, 1970 Inventor:

Assignee: Oak

Filed:

Appl. No.:

References Cited UNITED STATES PATENTS 8/1938 Mueller ..285/382.7 X 11/1964 Jackson et al ..174/89 X Primary Examiner-Darrell L. Clay Attorney-Frederick M. Arbuckle ABSTRACT A clamp-type coaxial connector having a one-piece clamp assembly. The clamp assembly includes a clamp nut, a clamp bushing, and a clamp ferrule. The nut and bushing each include a member adapted to coact with the member of the other element to secure the nut and bushing together in a manner such as to permit limited axial movement between the elements. The nut is adapted to coact with a connector body to secure the clamp assembly to the body and to drive the nut and bushing toward each other. A counter-bore exists in the nut and/or the bushing in which the ferrule is captivated, the counter-bore having an angled surface which coacts with the ferrule as the nut and bushing are driven toward each other to clamp the ferrule against the outer conductor of a coaxial cable.

12 Claims, 1 Drawing Figure number of initially loose parts which may, for example, be sold in a plastic bag and which are generally assembled in the field by the ultimate user. Particularly for miniature and sub-miniature clamp-connectors, many of these parts are quite small and are, therefore, difficult to handle and easy to lose. In addition to the difficulty in handling, the assembly operation is relatively complex and thus subject to error which could lead to a bad connection and circuit failures. Because of problems in handling the small parts and the complexity of the assembly operation, the labor time, and thus labor charges, for the connector mounting operation are relatively high. Other disadvantages with existing connectors'are that the small parts may be damaged in handling, thus providing another source of potential bad connections and, in most instances, the mounting of the connector deforms the clamp element, preventing the connector from being reused. Many existing connectors also rely on operator feel to determine when the clamping operation is complete and thus do not provide uniform pressure on the cable as would be the case with a built-in predetermined stop.

From the above it is apparent that many of the problems with existing clamp type connectors could be eliminated if most of the parts were provided as a pre-assembled clamp assembly. Such an assembly would eliminate the handling of small loose parts, reduce the risk of loss of such parts, simplify the assembly operation, thus reducing assembly time and cost, protect the small assembly parts against being damaged in transit and handling, and prevent improper assembly of the parts. A resilient clamp element could be provided to permit the connector to be reusable and a built-in stop could be provided in the clamp assembly to control the pressure on the cable.

It is therefore a primary object of this invention to provide an improved clamp-type coaxial connector.

A more specific object of this invention is to eliminate the large number of small loose parts which go to make up such a connector by providing a one-piece clamp assembly incorporating most of these parts.

Another object of this invention is to provide a connector of the type indicated above which may be reused.

Still another object of this invention is to provide a connector of the type indicated above with a built-in predetermined stop to control the pressure applied to the cable.

In accordance with these objects this invention provides a connector for a coaxial cable having an inner and outer conductor which connector includes a conductive body member and a clamp assembly. The body member has an axial bore and a rearwardly extending sleeve. A block of insulating material is secured in the bore and itself has a axial bore which is adapted to receive a contact member physically and electrically connected to the inner conductor of the cable. The clamp assembly is adapted to fit into the body sleeve and includes a clamp nut element, a clamp bushing element, and a clamp ferrule. The nut and bushing each include a member adapted to coact with the member of the other element to secure the nut and bushing together in a manner such as to permit limited axial movement between these two elements. The member on one of these elements may be a resilient projection with a raised portion on its end which is adapted to coact with a raised portion on a projection of the other element to secure the elements together. The clamp ferrule is captivated between the nut and bushing when they are secured together with the clamp nut including means for coacting with the body sleeve to secure the assembly in the sleeve and to drive the nut and bushing toward each other. The nut and bushing each have an axial bore which bores are alined when the elements are secured together and which bores are sized to receive the outer conductor of the cable.

The nut and/or the bushing have a counter-bore being at the surface of the element adjacent the other element. This angled surface is adapted to coact with the clamp ferrule to clamp the ferrule against the outer conductor when the nut and bushin are driven toward each other.

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawing.

The single FIGURE is an axial cut-away view of a preferred embodiment of the invention.

Referring now to the figure, it is seen that the connector 10 consists of a body 12 having a rearwardly extending sleeve 14 and a clamp assembly 16. Body 12 is of standard construction and includes a bore 18 having a counter-bore therein in which is secured a block 20 of insulating material. A coupling nut 22 is secured to body 12 by a retaining ring 24. A gasket 26 is provided between body 12 and coupling nut 22 to provided sealing when the connector shown in the figure is coupled with a mating connector.

Clamp assembly 16 consists of a clamp nut 28, a clamp bushing 30, and a cable clamp or a clamp ferrule 32. Clamp nut 28 has an external thread 34 which is adapted to coact with an internal thread 36 on body sleeve 14 in a manner to be described shortly to secure the body and clamp assembly together and to perform the clamp operation. Clamp nut 28 also has a plurality of resilient fingers 38 extending from its internal end which fingers may be formed by slotting a sleeve. Each finger terminates in an internal lip or projection 40. Clamp bushing 30 has a rearwardly projecting sleeve 42 which terminates in an outwardly facing lip or projection 44. The outer leading edge 46 of projection 44 is angled so as to permit fingers 38 to ride up and over projection 44 during assembly of the parts. Once the clamp nut and clamp bushing are assembled the lips 40 and 44 coact to secure the elements together forming a one-piece clamp assembly. Clamp ferrule 32 is captivated between these two elements. Lip 40 is, however, free to move between the position shown in the figure where it is against projection 44, to a position adjacent shoulder 48 of bushing 30, thus permitting limited movement in the axial direction between the nut and bushing.

Nut 28 has an axial bore 50, bushing 30 an axial bore 52, and ferrule 32 an axial bore 54. When the elements of the clamp assembly have been assembled, the bores 50, 52 and 54 are alined to form a single bore which is sized to accept the outer conductor 56 of a coaxial cable 58. Bore 50 has a counter-bore 60, the upper surface of which is at an angle to the axis of the connector, while bore 52 has a counter-bore 62 with a similar angled surface. When the elements are positioned as shown inthe figure, the distance between rear shoulder 61 of counter-bore 60 and rear shoulder 63 of counter-bore 62 is greater than the width of ferrule 32. As will be seen shortly, this distance controls the relative axial movement of the elements. The final element of the clamp assembly is a sealing gasket 64 which is mounted in a forward counterbore of bushing 30.

In use, outer conductor 56 is stripped back a predetermined distance and insulator 66 of cable 58 is then stripped back to expose inner conductor 68. A contact element 70, which is shown as being a male element in the figure but may be either male or female, is then mounted on inner conductor 68 and secured to the conductor as by use of a drop of solder 72. The cable is then passed through internal bores 50, 52 and 54 of clamp assembly 16, thus mounting the assembly on the cable, and contact 70 is passed through an axial bore '74 in insulating block 20 as body 12 is mounted on the cable. The movement of body 12 onto the cable is terminated when outer conductor 56 butts against, and makes electrical contact with rear wall 78 of body 12. Clamp assembly 16 may then be moved forward into sleeve 14 of body 12 and secured to the body by rotating nut 28 to engage screw threads 34 with screw threads 36. When nut 28 is screwed beyond the position shown in the figure, nut 28 continues to move into sleeve 14 while further movement of bushing 30 is prevented by the bushing butting against rear wall 78 of body 12. This results in axial movement between nut 28 and bushing 30. As inclined surfaces 60 and 62 move toward each other, ferrule 32 is compressed between them and is thus clamped against outer conductor 56 of coaxial cable 58. The rotation of nut 28 is terminated when the side edges of ferrule 32 butt against shoulders 61 and 63. The clamping force exerted by ferrule 32 against outer conductor 56 is thus controlled. Ferrule 32 may be constructed of a resilient conducting or non-conducting material so that when clamp nut 28 is unscrewed, returning the elements to the positions shown in the figure, the ferrule returns to its original dimensions permitting the connector to be reused.

A clamp-type coaxial cable connector having a one-piece clamp assembly has thus been provided. While in the preferred embodiment of the invention, the clamp nut and body sleeve have been shown as being secured together by a screw thread, other equivalent means, such as a cam pin and cam track, might be utilized. Further, while projection 38 on clamp nut 28 has been shown as being resilient for the preferred embodiment of the invention, this element could be rigid and projection 42 of bushing 30 could instead be the resilient member. Other similar modifications could be made in the captivation mechanism. Similarly, while both a counterbore 60 and a counter bore 62, each having an angled surface, have been shown in the figure, a single angled surface could be utilized to perform the clamping function.

Thus, while the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be apparent to those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

l. A connector for a coaxial cable having a inner and an outer conductor comprising:

a conductive body member having an axial bore and a rearwardly extending sleeve;

a block ofinsulatin'gmatqr i al in said bore, said block having an axial bore;

a contact member aduptedito be positioned in said bore and to be physically and electrically connected to said inner conductor; and

a clamp assembly fitted into said body sleeve, said assembly including a clamp nut element, a clamp bushing element and a clamp ferrule, said nut element and bushing element each including a member coacting with the member of the other element to secure said nut element and bushing element together while permitting limited axial movement between the elements, said ferrule being captivated between said elements, said nut element including means coacting with said sleeve to secure said assembly in said sleeve and drive said elements toward each other, said nut element, ferrule and bushing element each having an axial bore which bores are aligned and which bores are adapted to receive said outer conductor, a counter-bore in at least one of said elements, said counter-bore having a surface at an angle to the axis of the assembly and being located in the end of said element adjacent the captivated ferrule, said surface being adapted to coact with said ferrule to clamp said ferrule against said outer conductor.

2. A connector of the type described in claim 1 wherein the members on said nut element and bushing element are projections having a lip at their end, the projection of at least one of said elements being resilient.

3. A connector of the type described in claim 2 wherein the projection of said nut element is in the form of a plurality of resilient fingers.

4. A connector of the type described in claim 2 wherein the engaging surfaces of said lips are perpendicular to the connector axis and wherein the leading edge of at least one of said lips is angled to permit easy assembly of the elements.

5. A connector of the type described in claim 4 wherein each of said elements has a shoulder substantial] parallel to the engaging surface of the element lip and space a predetermined distance from said engaging surface, and wherein the lip of an element may move between a position against the engaging surface of the mating lip of the other element and a position against the shoulder of the other element.

6. A connector of the type described in claim 1 wherein said sleeve in internally threaded; and wherein the coacting meanS on said nut element is an external thread.

7. A connector of the type described in claim 1 wherein said body has a wall at the rear of said sleeve; wherein said bushing element butts against said wall in a predetermined partially assembled condition of said body and assembly; and wherein continued operation of the coacting means to assemble said body and assembly past said predetermined condition drives said nut element toward said bushing element with the captivated ferrule being compressed by the angled counter-bore surface to effect the desired clamping action.

8. A one-piece clamp assembly for a coaxial connector, said connector having a conductive body member and being adapted to be secured to a coaxial cable having an inner and an outer conductor, comprising:

a clamp nut element having means for coacting with said body to secure said assembly to said body;

a clamp bushing element;

said nut element and bushing element each including a member coacting with the member of the other element to secure the elements together while permitting limited axial movement between the elements;

a clamp ferrule captivated between said nut element and bushing element;

an axial bore adapted to accept said outer conductor, said bore being formed through the assembled nut element, bushing element and ferrule; and

a counter-bore having a surface at an angle to the axis of saidbore formed in at least one of said elements in the end thereof adjacent said ferrule, said angled surface being adapted to coact with said ferrule as said nut element and bushing element are moved axially toward each other to clamp said ferrule against said outer conductor.

9. An assembly of the type described in claim 8 wherein the members on said nut and bushing elements are projections having a lip at their end, the projection of at least one of said elements being resilient.

10. An assembly of the type described in claim 9 wherein the projection on said nut element is in the form of a plurality of resilient fingers.

11. An assembly of the type described in claim 9 wherein the engaging surfaces of said lips are perpendicular to the connector axis and wherein the leading edge of at least one of said lips is angled to permit easy assembly of the elements.

12. An assembly of the type described in claim 11 wherein each of said elements has a shoulder substantially parallel to the engaging surface of the element lip and spaced a predetermined distance from said engaging surface, and wherein the lip for an element may move between a position against the engaging surface of the mating lip of the other element and a position against the shoulder of the other element. 

1. A connector for a coaxial cable having a inner and an outer conductor comprising: a conductive body member having an axial bore and a rearwardly extending sleeve; a block of insulating material in said bore, said block having an axial bore; a contact member adapted to be positioned In said bore and to be physically and electrically connected to said inner conductor; and a clamp assembly fitted into said body sleeve, said assembly including a clamp nut element, a clamp bushing element and a clamp ferrule, said nut element and bushing element each including a member coacting with the member of the other element to secure said nut element and bushing element together while permitting limited axial movement between the elements, said ferrule being captivated between said elements, said nut element including means coacting with said sleeve to secure said assembly in said sleeve and drive said elements toward each other, said nut element, ferrule and bushing element each having an axial bore which bores are aligned and which bores are adapted to receive said outer conductor, a counter-bore in at least one of said elements, said counter-bore having a surface at an angle to the axis of the assembly and being located in the end of said element adjacent the captivated ferrule, said surface being adapted to coact with said ferrule to clamp said ferrule against said outer conductor.
 2. A connector of the type described in claim 1 wherein the members on said nut element and bushing element are projections having a lip at their end, the projection of at least one of said elements being resilient.
 3. A connector of the type described in claim 2 wherein the projection of said nut element is in the form of a plurality of resilient fingers.
 4. A connector of the type described in claim 2 wherein the engaging surfaces of said lips are perpendicular to the connector axis and wherein the leading edge of at least one of said lips is angled to permit easy assembly of the elements.
 5. A connector of the type described in claim 4 wherein each of said elements has a shoulder substantially parallel to the engaging surface of the element lip and spaced a predetermined distance from said engaging surface, and wherein the lip of an element may move between a position against the engaging surface of the mating lip of the other element and a position against the shoulder of the other element.
 6. A connector of the type described in claim 1 wherein said sleeve in internally threaded; and wherein the coacting means on said nut element is an external thread.
 7. A connector of the type described in claim 1 wherein said body has a wall at the rear of said sleeve; wherein said bushing element butts against said wall in a predetermined partially assembled condition of said body and assembly; and wherein continued operation of the coacting means to assemble said body and assembly past said predetermined condition drives said nut element toward said bushing element with the captivated ferrule being compressed by the angled counter-bore surface to effect the desired clamping action.
 8. A one-piece clamp assembly for a coaxial connector, said connector having a conductive body member and being adapted to be secured to a coaxial cable having an inner and an outer conductor, comprising: a clamp nut element having means for coacting with said body to secure said assembly to said body; a clamp bushing element; said nut element and bushing element each including a member coacting with the member of the other element to secure the elements together while permitting limited axial movement between the elements; a clamp ferrule captivated between said nut element and bushing element; an axial bore adapted to accept said outer conductor, said bore being formed through the assembled nut element, bushing element and ferrule; and a counter-bore having a surface at an angle to the axis of said bore formed in at least one of said elements in the end thereof adjacent said ferrule, said angled surface being adapted to coact with said ferrule as said nut element and bushing element are moved axially toward each other to clamp said ferrule against said outer conductor.
 9. An assembly of the type described in claim 8 wherein the members on said nut and bushing elemEnts are projections having a lip at their end, the projection of at least one of said elements being resilient.
 10. An assembly of the type described in claim 9 wherein the projection on said nut element is in the form of a plurality of resilient fingers.
 11. An assembly of the type described in claim 9 wherein the engaging surfaces of said lips are perpendicular to the connector axis and wherein the leading edge of at least one of said lips is angled to permit easy assembly of the elements.
 12. An assembly of the type described in claim 11 wherein each of said elements has a shoulder substantially parallel to the engaging surface of the element lip and spaced a predetermined distance from said engaging surface, and wherein the lip for an element may move between a position against the engaging surface of the mating lip of the other element and a position against the shoulder of the other element. 